<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>圣杯布局flexV2</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }

        html, body{
            width: 100%;
            height: 100%;
        }
        body {
            display: flex;
            flex-direction: column;
        }

        .box {
            display: flex;
            flex-direction: column;
            width: 100%;
            height: 100%;
        }
        main {
            height: 100%;
            flex: 1;
            background-color: #000;

        }

        header, footer {
            height: 10px;
            background-color: cyan;
        }

    </style>
</head>
<body>
<div class="box">
<header></header>
<main>
    <aside></aside>
    <main></main>
    <aside></aside>
</main>
<footer></footer>
</div>
</body>
</html>
